Control system



Dec. 28, 1965 sTlNE CONTROL SYSTEM Filed 001 14, 1963 T0 IWWEP SUPPL Y INVENTOR. RICHARD L. ST/IVE ATTORNEY United States Patent 3,225,989 CONTROL SYSTEM Richard L. Stine, Carditf by the Sea, Calif., assignor to General Dynamics Corporation, Rochester, N.Y., a corporation of Delaware Filed Oct. 14, 1963, Ser. No. 315,867 1 Claim. '(Cl. 226-44) This invention relates to a paper loop control mechanism and, more particularly, to a paper loop control mechanism for high-speed electronic printers, wherein the paper travels at an extremely high rate of speed.

In the prior art, there have been many methods and systems with the resultant apparatus for performing these methods and systems to control a loop of paper, or other strip material, in printing machines In some cases, the commonly used dancer bar has been used and is well know to those familiar in the art of printers and paper machine techniques.

The present invention simplifies the threading of the paper into the machine with no obstructions to encounter, such as the dancer bar.

The prime advantages of the present invention are that it creates practically zero drag in the paper system, it uses no unconventional or expensive parts, it is practically free from maintenance and performs well for the purpose intended.

It is an object of the present invention to provide a control mechanism for controlling the paper, or other strip material, in a loop and maintaining said loop, regardless of the rate of speed at which the paper is used, and does not depend on continuous usage.

It is a further object of the present invention to provide a sutficient paper loop between the paper supply roll and the printer, so that the paper does not become ta-ut and tear, or mutilate the paper supplied to the printer.

It is still a further object of the present invention to provide a maximum paper loop as a storage means that will be available upon the demand of the stepping motor which supplies the right amount of paper to the printer.

It is another object of the present invention to provide a minimum paper loop during the printing cycle for safe and eflicient operation.

In accordance with the present invention, a control system is provided for delivering a continuous strip of paper into an electronic printer as the demand requires. The demand for paper may be intermittent or continuously run through the printing cycle. The paper feed to the printer mechanism is controlled by means of a paper loop actuating a control system for energizing or deenergizing the clutch of the paper-feed roller. Thls control system will provide a paper loop of either maximum or minimum size that can be used as a storage means and for providing a sufiicient paper loop between the paper supply roller and the printer, so the paper does not become taut and tear said paper during printlng operation.

Further objects and advantages of the invention Wlll become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the invention, reference may be had to the accompanying drawing, in which:

FIG. 1 discloses the preferred embodiment of the present invention; and

FIG. 2 discloses a schematic diagram of the operation of a paper loop control actuator showing minimum and maximum controlled paper l-oops.

In FIG. 1 of the drawing, the numeral indicates a portion of a high-speed electronic printer, showing the paper-feed system, and discloses the invention for controlling the paper loop. The paper-feed clutch 12 is coupled to the paper-feed roller 14, which feeds the paper P from the supply roll (not shown) in the direction of the arrow to the printer stepping motor (not shown) in this embodiment.

Paper-feed roller 14 with its spring-loaded pinch roller 16 will feed the paper P only when the paper-feed clutch 12 is energized; pinch roller 16 holds the paper firm to the paper-feed roller 14 so as to avoid paper slipping and to be ready for immediate paper delivery, as demanded. Upon threading of paper P into the printer, a paper loop must be provided in the paper loop area 34. This loop is usually common to all paper machines with one end of the paper P of the paper loop over guide roller 20. After the paper is threaded into the machine and operation begins, the present invention automatically controls the paper loop 18.

When the high-speed electronic printer is in operation, the paper-feed motor (not shown) is energized and is free-running with a clutch 12 coupled between the motor shaft and the shaft of the paper-feed rolled 14. At such time in the operation when the stepping motor (not shown) demands paper for the printer from the paper supply roll, the stepping motor starts the paper travel into the printer from the paper loop 18 in storage, as shown in loop area 34 of FIG. 1. As the stepping motor keeps demanding more paper, the paper loop 18 starts to diminish. As the loop 18 gets smaller, the actuator lever 22, with a resilient coil spring 30 fastened to actuator 22 and a stationary bar 32, will follow the paper loop 18 up to a point of a predetermined minimum loop 40, as shown in FIG. 2. At this desired point, the rotation of shaft 26 with a milled fiat 24 thereon and pivoted by actuator lever 22 will move arm 36 down through its roller 36a on the milled flat 24 to a position where microswitch 38 will operate to the ON position, thus energizing the paper-feed clutch 12. The paper-feed roller 14 will start to feed paper P off the paper supply roll to the printer. During this cycle of operation, the minimum loop 40 will be maintained. Shaft 26 with suitable bearings is mounted between mounting plates 28 and 30.

When the stepping motor stops and no demand for paper is necessary, the paper being fed from the paper supply roll continues to travel into the paper loop area 34. As the size of the paper loop 18 increases, the increased weight of the paper forces down the actuator 22 to a predetermined distance, as shown at D in FIG. 2, thus creating a desired maximum loop 42 in FIG. 2. During the time actuator lever 22 is forced down and being pivoted on said shaft 26 with said milled flat 24, arm 36 will move up through its roller 36a on the milled flat 24 to a position where microswitch 38 will operate to the OFF position, thus deenergizing the paper-feed clutch 12 and stopping paper-feed roller 14. The maximum paper loop 42 now in storage area 34 is ready for another cycle of the high-speed electronic printer.

While there has been shown and described what is at present considered to be the preferred embodiment of the invention, other modifications will readily occur to those skilled in the art. It is not, therefore, desired that the invention be limited to the specific arrangement shown and described, and it is intended in the appended claim to cover all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

In a strip paper feed mechanism which comprises a paper feed roller, a paper guide roller, and a loop of paper between said rollers, wherein paper is withdrawn from said loop at said guide roller and is fed into said loop at said feed roller; the combination therewith of a paper loop control system including an actuating lever having its distal end in contact with thebottom surface of said paper loop and its proximate end fixed to a rotatably mounted shaft, spring biasing means having one end thereof connected to said lever at a point intermediate said proximate and distal ends of said lever, the other end of said biasing means being secured to a fixed point located above said lever for urging said lever upward against the weight of said paper loop, whereby the angular position of said shaft is determined by the size of said paper loop, selectively energizable means for positively rotating said feed roller to feed paper into said loop solely in response to the energization thereof, said selectively energizable means including a plungertype switch having a movable actuator arm for effecting the energization of said selectively energizable means in response to said arm achieving a first predetermined position and for effecting the deenergization of said selectively energizable means in response to said arm achieving a second predetermined position, coupling means coupling said arm to said shaft for moving said arm between said first and second predetermined positions thereof in accordance with the angular position of said shaft, said arm achieving said first predetermined position thereof at a given minimum size of said paper loop and said arm achieving said second predetermined position thereof at a given maximum size of said paper loop, said coupling means includes a milled flat portion on said shaft, a cam roller riding on said milled flat portion, said cam roller being attached to the end of said arm for moving said arm in response to angular rotation of said shaft.

References Cited by the Examiner UNITED STATES PATENTS 4/ 1944 Calleson et al 226-44 X 8/1956 De La Motte 242-78.7 

